hi! my practice amp is an old SWR workingman 15 combo (doñy know how old, but its in semi bad conditions) i brought it used 1 year ago and dont use it as my main amp. the problem is that when i play loud (specially with lots of low end) the amp clips, distorts, and stop working for some seconds. well, is this normal in these amps? my concern is that i hasnt got the much volumen comparing it with other 100 watt amp, so i may have something wrong... is there anything i can do to check if everything is ok?